Direct evidence of active surface reconstruction during oxidative dehydrogenation of propane over VMgO catalyst

Journal Article · Sat Jul 25 00:00:00 EDT 1998 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1998.2095· OSTI ID:653323

Pantazidis, A; Mirodatos, C ^[1]; Burrows, A; Kiely, C J ^[2]

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1. C.N.R.S., Villeurbanne (France). Inst. de Recherches sur la Catalyse
2. Univ. of Liverpool (United Kingdom). Dept. of Materials Science and Engineering

This paper presents a thorough investigation of an optimized VMgO catalyst (14 wt% V) for the oxidative dehydrogenation of propane, carried out in order to elucidate the nature and behavior of the active surface. The catalyst morphology and the surface composition are studied by means of HREM, XPS, UV-vis, XRD, and in-situ electrical conductivity techniques, as a function of the gaseous environments of the catalyst. The active surface is shown to be essentially a monolayer of amorphous VO{sub 4}{sup 3{minus}} units scattered over the magnesia as isolated and polymeric species. These surface vanadia units are found to stabilize an unusual polar (111) orientation of MgO up to temperatures of 800 C. A direct and outstanding evidence of a totally reversible phenomenon of order/disorder restructuration of this V overlayer is provided in conjunction with the redox state of the surface depending on the properties of the surrounding atmosphere (reductive or oxidative). These fast surface phenomena are assumed to determine the elementary steps of propane activation within the overall oxidative dehydrogenation of propane (ODHP) process.

• OSTI ID: 653323
• Journal Information: Journal of Catalysis, Vol. 177, Issue 2; Other Information: PBD: 25 Jul 1998
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
10 SYNTHETIC FUELS
PROPANE
DEHYDROGENATION
OXIDATION
VANADIUM OXIDES
MAGNESIUM OXIDES
CATALYTIC EFFECTS
ORDER-DISORDER TRANSFORMATIONS